When a vehicle (hereinafter, also referred to as a preceding vehicle) runs, if the driver of another vehicle (hereinafter, also referred to as a following vehicle) running behind the preceding vehicle feels that a driving state which the driver wants is obstructed by the preceding vehicle, the following vehicle may tailgate the preceding vehicle (e.g. drive too closely behind the preceding vehicle). Tailgating includes high-risk acts such as the act of following a preceding vehicle too closely.
In general, most of drivers whose tailgate are habitual tailgaters, and such habitual tailgaters rarely recognize that they are tailgating. However, for now, there is no means effective in giving a warning to such habitual tailgaters. Therefore, in order to prevent accidents, preventive safety centering on self-defense of drivers is important.
In the related art, when a subject vehicle is tailgated by another vehicle, in order to determine whether the tailgating vehicle is a vehicle having tailgated the subject vehicle in the past, for example, the driver of the subject vehicle needs to look in the rearview mirror or turn his head to check the following vehicle. Therefore, the burden on the driver is large.
There has been proposed a driving supporting device for determining the state of another vehicle around a subject vehicle equipped with the driving supporting device, and determining the possibility that another vehicle will tailgate the subject vehicle equipped with the driving supporting device, at least on the basis of the result of determination on the state of another vehicle, and performing notification control for the driver of the subject vehicle equipped with the driving supporting device on the basis of the result of determination on the possibility (see Patent Document 1).
In Patent Document 1, a risk notification for notifying the driver that there is a risk is performed as notification control.
Patent Document 1: Japanese Patent Application Publication No. 2006-205773A
However, the technology disclosed in Patent Document 1 just performs the risk notification for notifying the driver that there is a risk, and does not consider how the driver of the subject vehicle equipped with the driving supporting device determines whether another vehicle is driven by a habitual tailgater and how the driver of the subject vehicle equipped with the driving supporting device ensures preventive safety mainly with a focus on self-defense.